Colleges are considered 'small' when they are less than 5,000 students, 'mid-sized' between 5,000 and 15,000 students, and so on.
College Sizes: Small, Medium, or Large | CollegeData
NAIS - Key Enrollment Trends: How Small Schools Are Faring
How important is school size? | Parenting
From the Archives] Small is Beautiful: The value of small schools | 21k12
Small Schools: The Myths, Reality, and Potential of Small Schools | by Joe Brooks | Community Works Journal: Digital Magazine for Educators | Medium
Essay About Large or Small School
15 Interior Design Schools Worth Applying to | Architectural Digest